From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 37F972063E9 for ; Thu, 13 Feb 2025 04:42:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739421768; cv=none; b=BQ2kQOhKp30mgCtW7DFGJTqqeNnuSfZ0kKxqBhuntj/kp9ozcs4gkENt9LQG9cJF2Uf41Qp1GqfMSgEDidsBVMLg3wEiNjC2F4DB1kCL3Tamr9ahnFKg7I9zmWSbch5V2oiTOcPtaUgCTR6GLJtyDN9l5Tiln+eY3DKK90N6I9A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739421768; c=relaxed/simple; bh=eLVm69GxHTnCc1sbYQKNaMFNQ35O1pvos4zHtxlfu20=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=gQVKfE2mtKab+cPMyUle5T9uv+4GzblXlINGGEIK016Ri/YZtbv2TYtyrLJciC+4iRGf+V7RGhc1V1+dxY8xkl0u6SzENf1xVYcdlEj0WqbUcaJK4AIxSprQ8Y/cRGtDzQ3eUN28d4TXUu597Y8Xa4mNbBd9thNu8CPquJLHd6E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=mUTrnVFO; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="mUTrnVFO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 95174C4CEED; Thu, 13 Feb 2025 04:42:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1739421767; bh=eLVm69GxHTnCc1sbYQKNaMFNQ35O1pvos4zHtxlfu20=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=mUTrnVFO6qj6gnZjh5ZPRqwf1LyviRTi9EuBJ56tQRMefvVuPQhjTXyt5q6R27+c8 MmuC/YxLTgtPNyCoL3o7OUYS7oc3PazpRd+g9m2JPjVvf2T5u1Dn4vvnwb1XEf8Z8h W9Qmh2dygg0pOS44iA+8zYi7czFVHyg2JUD8mWAionqvqhiGYQ43SuCCBtw02ksULr tqkZ2dJ3Q3hZZzmIq/zcCYyEEmPvZA10Yb3+KejHVSpoBHHSOtqPp3vVu90IWfF69A bmHGiRmSNSYErWsI4pfOjSHkT+rq/Tw04dzU0rtD0jpoqKAMgjyjieuJg3lAysUr6w lHbbD3wMpleaw== Date: Wed, 12 Feb 2025 20:42:47 -0800 From: "Darrick J. Wong" To: Hans Holmberg Cc: hch , Carlos Maiolino , "linux-xfs@vger.kernel.org" Subject: Re: [PATCH 39/43] xfs: support write life time based data placement Message-ID: <20250213044247.GH3028674@frogsfrogsfrogs> References: <20250206064511.2323878-1-hch@lst.de> <20250206064511.2323878-40-hch@lst.de> <20250212002726.GG21808@frogsfrogsfrogs> Precedence: bulk X-Mailing-List: linux-xfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Wed, Feb 12, 2025 at 01:29:21PM +0000, Hans Holmberg wrote: > On 12/02/2025 01:27, Darrick J. Wong wrote: > > On Thu, Feb 06, 2025 at 07:44:55AM +0100, Christoph Hellwig wrote: > >> From: Hans Holmberg > >> > >> Add a file write life time data placement allocation scheme that aims to > >> minimize fragmentation and thereby to do two things: > >> > >> a) separate file data to different zones when possible. > >> b) colocate file data of similar life times when feasible. > >> > >> To get best results, average file sizes should align with the zone > >> capacity that is reported through the XFS_IOC_FSGEOMETRY ioctl. > >> > >> For RocksDB using leveled compaction, the lifetime hints can improve > >> throughput for overwrite workloads at 80% file system utilization by > >> ~10%. > > > > The code changes look mostly ok, but how does it do at 40% utilization? > > 99%? Does it reduce the amount of relocation work that the gc must do? > > The improvement in data placement efficiency will always be there, > reducing the number of blocks requiring relocation by GC, but the impact > on performance varies depending on how full the file system is. > > At 40% utilization there is almost no garbage collection going on, so the > impact on throughput is not significant. At 99% the effects of better > data placement should be higher. Would you mind pasting that into the commit message? --D > Cheers, > Hans >